CVE-2026-2616: Beetel 777vr1 Auth Bypass Vulnerability

CVE-2026-2616 Overview

A hard-coded credentials vulnerability has been discovered in the Beetel 777VR1 router affecting firmware versions up to 01.00.09. The vulnerability exists within an unknown function of the Web Management Interface component, allowing unauthorized access through embedded credentials that cannot be changed by end users. Exploitation requires network adjacency, meaning attackers must be on the local network to take advantage of this flaw. The exploit has been publicly disclosed, and the vendor did not respond to early disclosure attempts.

Critical Impact

Attackers on the local network can leverage hard-coded credentials to gain unauthorized administrative access to the router's Web Management Interface, potentially leading to complete device compromise, network traffic interception, and configuration manipulation.

Affected Products

• Beetel 777VR1 Firmware (versions up to 01.00.09)
• Beetel 777VR1 Hardware

Discovery Timeline

• February 17, 2026 - CVE-2026-2616 published to NVD
• February 19, 2026 - Last updated in NVD database

Technical Details for CVE-2026-2616

Vulnerability Analysis

This vulnerability represents a classic embedded device security flaw classified as CWE-259 (Use of Hard-Coded Password). The Beetel 777VR1 router contains credentials embedded directly within its firmware that provide access to the Web Management Interface. These credentials cannot be modified by device administrators, creating a persistent backdoor that affects all deployed instances of the vulnerable firmware versions.

Hard-coded credentials in network equipment are particularly dangerous because they provide consistent, reliable access to all affected devices. Once an attacker discovers the credentials—whether through firmware analysis, reverse engineering, or public disclosure—every vulnerable device becomes immediately accessible. This vulnerability requires adjacent network access, meaning the attacker must be connected to the same local network segment as the target router.

The impact of successful exploitation is severe, enabling attackers to gain full administrative control over the router. This access could be leveraged to modify DNS settings for phishing attacks, intercept or redirect network traffic, create persistent backdoors, or pivot to other devices on the network.

Root Cause

The root cause is the use of hard-coded credentials embedded in the router's firmware (CWE-259). These static authentication values are compiled into the device software, making them impossible to change without a firmware update. This represents a fundamental security design flaw where developers prioritized convenience over security, failing to implement proper credential management mechanisms such as unique per-device passwords or mandatory password changes during initial setup.

Attack Vector

The attack requires adjacent network access, meaning an attacker must first gain access to the same local network where the vulnerable Beetel 777VR1 router is deployed. This could be accomplished through connecting to the same WiFi network, physical access to the network infrastructure, or compromising another device on the network first.

Once on the local network, the attacker can access the router's Web Management Interface and authenticate using the hard-coded credentials. No user interaction is required, and successful exploitation grants full administrative privileges over the device. The attack complexity is low since the credentials are static and publicly disclosed.

The vulnerability has been publicly disclosed with reproduction steps available on GitHub, significantly lowering the barrier to exploitation.

Detection Methods for CVE-2026-2616

Indicators of Compromise

• Unexpected successful logins to the router's Web Management Interface from unrecognized IP addresses
• Configuration changes not initiated by authorized administrators, particularly DNS settings, firewall rules, or remote access configurations
• New or modified port forwarding rules that could indicate traffic redirection
• Unusual administrative sessions occurring outside normal maintenance windows

Detection Strategies

• Monitor authentication logs on the router for login attempts using known default or hard-coded credential patterns
• Implement network access control (NAC) to restrict which devices can communicate with the router's management interface
• Deploy network monitoring to detect unusual traffic patterns to/from the router's administrative ports
• Conduct periodic configuration audits to identify unauthorized changes

Monitoring Recommendations

• Enable and export router syslog data to a centralized SIEM for authentication event correlation
• Configure alerts for any administrative access to the Web Management Interface
• Implement network segmentation monitoring to detect lateral movement attempts post-compromise
• Regularly scan the network for devices running vulnerable Beetel 777VR1 firmware versions

How to Mitigate CVE-2026-2616

Immediate Actions Required

• Restrict access to the router's Web Management Interface to trusted IP addresses only using firewall rules or access control lists
• Implement network segmentation to isolate the router's management interface from general user traffic
• Consider replacing affected devices with routers from vendors that have demonstrated security responsiveness
• Monitor for any signs of compromise and audit current router configurations for unauthorized changes

Patch Information

No patch is currently available from Beetel. The vendor was contacted early about this disclosure but did not respond. Device administrators should modify configuration settings where possible to reduce exposure and consider device replacement if the router is deployed in a security-sensitive environment.

Additional technical details and tracking information are available through VulDB.

Workarounds

• Disable remote management access to the Web Management Interface if not required for operations
• Place the router's management interface on a dedicated VLAN accessible only to network administrators
• Implement MAC address filtering as an additional layer of access control for management access
• Deploy an upstream firewall to restrict which devices can reach the router's administrative ports
• Consider using a VPN to access the management interface rather than direct network connectivity

# Example: Restrict management interface access via iptables on upstream device
# Block external access to router management port
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 443 -j DROP

# Allow only specific admin workstation
iptables -I FORWARD -s 192.168.1.100 -d 192.168.1.1 -p tcp --dport 80 -j ACCEPT
iptables -I FORWARD -s 192.168.1.100 -d 192.168.1.1 -p tcp --dport 443 -j ACCEPT